Chromosome Question

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Agronomy
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Chromosome Question

Post by Agronomy » Wed Jan 17, 2007 5:15 am

Snapdragon has a diploid number of 16 chromosomes. How many sister chromatids are present in prophase?

I'm confused on this question...is the answer 32?

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sachin
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Post by sachin » Wed Jan 17, 2007 2:40 pm

Diploid number of 16 means

16*2=32 chromosomes

sister chromatids present in prophase=32*2=64..
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Thanx!

Post by Agronomy » Wed Jan 17, 2007 3:57 pm

Why did you multiply the 16 x 2 and then by 2 again!?

If it has a diploid number of 16 chromosomes, then you would just multiply that by 2 to get the number of chromatids to get 32 right?

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Post by sachin » Wed Jan 17, 2007 4:28 pm

Then in prophase 'I' shaped chromosome becomes doubled by DNA replication and become 'X' shaped due to presence of sister chromatid...

so I multiplied by 2 again.

Remember there two 'I' shaped chromosomes in general.."II"

Then after synthesis they become..."XX"

And after cell division they again come to..."II" ; "II"
Senior Education Officer, BNHS, India. www.bnhs.org

Bitter Truth!
Who says reason for world war III will be Petrol?
Reason lies in two words "Me and Mine".

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Thanxx!!!

Post by Agronomy » Wed Jan 17, 2007 5:32 pm

Oh okay thanx!!! :-)

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